Diamond is the purest form of ________.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Carbon
Diamond is an allotrope of carbon: it is made of carbon atoms alone, each bonded to four others in a rigid three-dimensional network, which makes it the hardest natural substance. Graphite and fullerenes are other forms of the same element.
Why the other options are incorrect
Option (1) Charcoal — Incorrect. Charcoal is an impure, non-crystalline form of carbon made by heating wood without air.
Option (2) Coal — Incorrect. Coal is a fossil fuel of carbon mixed with hydrogen, sulphur and other matter.
Option (4) Wood — Incorrect. Wood is plant tissue, mainly cellulose and lignin, not a form of carbon.